Jim is a 15-year-old boy living in London. Briefly explain to Jim the legal position arising from the following scenarios: (a) In the morning Jim offers to wash his dad's car for 10. Having washed the car, his dad tells him that he changed his mind and does not pay Jim! (b) Later in the afternoon, Jim is out at the high street, when he sees in a shop his favourite skateboard being offered for 50, i.e. half the normal price. He enters the shop and asks to buy it at that price. The shopkeeper tells him that there has been a mistake on the price labelling and the price is 100 for the skateboard!